In any transportation industry, reliable communications systems are mandatory for avoiding serious, if not catastrophic, accidents. In the particular case of the railroads, the railroad central offices normally communicate through wired telecommunications links with a network of radio base stations, which are typically dispersed over very large geographical areas. The radio base stations in turn maintain wireless communication links with locomotives, service vehicles, and wayside systems operating within the base station coverage areas.
In reliability-critical communications systems, a failure of any link within a given communications path must be detected and quickly addressed. In the case of a railroad communications system, this must include detecting and addressing any failures occurring within the wired network between the railroad central office and each of the radio base stations.